The IRS has a 3 year statute of limitations to conduct an audit. This can be extended to 6 years for the under-reporting more than 25% of gross income. In an attempt to extend the statute of limitations, a taxpayer that correctly reported gross income, but overstated the basis in assets sold as part of the “Son of BOSS” tax shelter. the IRS claimed it had a 6 year period to audit. The Supreme Court said the IRS was wrong and the taxpayer could not be audited more than 3 years after filing the tax return.
Please see: United States v. Home Concrete & Supply LLC